Clinical evidence suggests a correlation between core body temperature and the frequency of sleep episodes. An artificial thermoregulatory system is completed which will permit core body temperature manipulation and hence, the evaluation of the efficacy of thermal regulation in the treatment of sleep disorders. Clinical trials are now performed on a regular basis. Simultaneous sleep recordings are obtained during both a non-manipulated and manipulated 24 hour period. Clinical studies are now underway and the data obtained so far suggests no interaction between sleep rhythms and body temperature. More studies are being performed to substantiate conclusively these findings. Reevaluation of clinical evidence has prompted an extensive effort to accumulate a larger, more complete data base of control subjects. Standard sleep recordings and temperature profiles of normal subjects are being taken before further intervention protocols are implemented.